Nesting box to hen ratio

We have a coop in progress and I have a few questions:
What should the ratio of nesting boxes to hens be? I will have 12 hens eventually and my husband is going to make 6 nesting boxes- is that enough? How far off the floor of the coop should the nesting boxes be? How do the chickens access them if they are off the floor a little?

I usually do it a little differently than most. I make a bigger size nesting box...about 24"x16 or so inches and let them all use the same one. Sometimes you'll find 4 or 5 are using it at the same time but as long as there is lots of bediing no eggs gt broken and it works great!

Before you go to bed, give your troubles to God...He'll be up all night anyway.

My boxes are a little larger too. Two hens sometimes get in at the same time. I have some hens that regularly argue over the same box! I have plenty to go around, but mine have their favorite ones!
Some of my boxes are close enough to the floor to just hop in, & others are on top of those, but smaller. They can fly up to the top of the lower boxes (like a shelf) & step into the top ones.